The invention relates to concrete inserts, ie., to apparatus which are embedded in concrete when it is poured and which, after the concrete hardens, provide a bore in the concrete for receiving a fastener such as a bolt or screw.
U.S. Pat. No. 3,685,783 discloses an anchor or insert having an internally threaded bore which receives an externally threaded dowel. The dowel is connected to a board which forms a part of a concrete mold form. When the board is removed from hardened concrete, the dowel is broken, leaving a portion of the dowel in the bore. This portion must be removed from the insert before a bolt or screw can be threaded into the bore.
U.S. Pat. No. 1,045,562 discloses a concrete insert which is nailed to a board, with the nails being secured in notches on the outside of the insert. When the board is removed from hardened concrete, the tips of the nails, which extend from the concrete, are sawed off or bent over.
Attention is also directed to the following U.S. patents:
______________________________________ Hilgeman 3,632,724 1/4/72 Naka 4,211,048 7/8/80 Ilukowicz 3,889,916 6/17/75 Kowell 3,764,066 10/9/73 Kowell 3,685,782 8/22/72 Murphy, et al. 1,157,895 10/26/15 Mess 4,084,780 4/18/78 ______________________________________